1. Field of the Invention
The present invention generally relates to a locking mechanism for an outboard motor and, more particularly, to a locking mechanism that includes a sliding rod within a tube in combination with a locking pin that prevents the rod from sliding within the tube and, since the rod is attached to a movable segment of the outboard motor, also prevents movement of the movable segment of the outboard motor relative to a stationary segment of the outboard motor or to the transom of a boat to which the outboard motor is attached.
2. Description of the Prior Art
Outboard motors are well known to those skilled in the art. Typically, outboard motors are provided with a bracket and at least one mechanism that allows the outboard to be tilted relative to its bracket and relative to the transom of a boat and also allows the outboard motor to be swiveled about a generally vertical centerline to allow steering of the boat.
Under certain circumstances, boat operators tilt the outboard motor up to a maximum position when the outboard motor is not in use. This situation can occur when the outboard motor is used as an auxiliary propulsion system, such as on sailboats or on boats powered by another outboard motor. Also, outboard motors are typically tilted to a maximum position when the boat operator is towing the boat on a trailer. During this type of operation, with the outboard motor tilted to its maximum upward position, the movable segment of the outboard motor, comprising the engine, cowl, driveshaft housing, and lower gearcase, can move to a rotated position relative to its steering axis and to a stationary segment of the outboard motor which comprises a bracket that is attachable to a transom of a boat. With the movable segment of the outboard motor turned to non central extreme position while tilted upward to a maximum position, shock loads can exert potentially damaging forces on various components of the outboard motor. For example, repeated shock loads can cause fatigue of certain support and structural members such as support brackets. These shock loads can either be caused by wave action if the boat is in operation on water or, alternatively, by undulations in a road surface if the boat is being transported on a trailer behind an automobile.
Various types of locking mechanisms are known to those skilled in the art. U.S. Pat. No. 5,868,591, which issued to Kleeman et al on Feb. 9, 1999, discloses a swivel lock for an outboard motor. First and second latch mechanisms are provided that allow a boat operator to prevent the movable and stationary portions of an outboard motor from moving relative to each other. This device can be used during shipping, transportation, or use of an outboard motor in conjunction with a sailboat in which the rudder of the sailboat is used for steering, and it is desirable to maintain the movable and stationary portions of an outboard motor rigidly with respect to each other. A first latch mechanism is attached to the movable portion of the outboard motor, and a second latch mechanism is attached to the stationary portion of an outboard motor. The second latch portion is rotatable to place a receptacle into a region where a locking device can retain it.
U.S. Pat. No. 4,863,505, which issued to Hervat et al on Sep. 5, 1989, describes an outboard motor tilt lock device. The marine propulsion device comprises a transom bracket adapted to be mounted on the transom of a boat and having a side and upper surface. It also comprises a swivel bracket mounted on the transom bracket for pivotal movement relative to the transom bracket about a generally horizontal tilt axis and between an operating position and a raised position. A tilt lock shaft has first and second ends extending through the swivel bracket along a second generally horizontal axis spaced rearwardly from and substantially parallel to the tilt axis. A lever member mounted on the shaft and including a contact pad extending parallel to and radially offset from the second axis and further including at least one leg extending substantially perpendicularly relative to the contact pad are also provided.
U.S. Pat. No. 5,582,527, which issues to Nakamura on Dec. 10, 1996, describes a steering system for an outboard motor. The steering device for the outboard motor retains the motor under constant, although adjustable, pressure to releasably hold it in a plurality of secured positions. Moreover, the releasable restraining device permits rotation of the motor about the tilt and trim axis while the retaining device is in any of a plurality of retained positions.
U.S. Pat. No. 5,328,394, which issued to Onoue et al on Jul. 12, 1994, described a steering system for a marine propulsion unit. A hydraulic assisted mechanism for marine propulsion drives wherein the hydraulic assist is operated by a control valve having its valve element actuated by a wire actuator that is operated by the steering mechanism. The actuating element that interconnects the wire actuator to the control valve element is supported for movement in a variety of embodiments so as to confine the movement in the same direction as the valve element.
U.S. Pat. No. 4,961,392, which issued to Ballard on Oct. 9, 1990, describes a self locking mechanical steering helm. The steering helm for a boat includes a worm gear set having a worm fixed on the steering wheel shaft and a worm gear clustered with a cable sprocket for controlling the movement of the steering which extends to the outdrive of the boat.
U.S. Pat. No. 3,808,851, which issued to Kargus et al on May 7, 1974, describes an outboard motor lock. The invention relates to an improved locking device for preventing the theft or accidental dislodgment during use of outboard motors. The device consists of a one piece slotted tubular member which is adapted to slide over and to engage and lock against member the heads of the clamp screws for the motor supporting bracket. This tubular member is provided with a series of aligned holes adapted to receive the shackle of a padlock or equivalent locking means in such manner that removal of the tubular member from locking engagement with the heads of the clamping screws is effectively prevented.
U.S. Pat. No. 4,521,201, which issued to Watanabe on Jun. 4, 1985, describes a steering device for an outboard motor. The steering device for an outboard motor releasably restrains the motor in a predetermined position which can be automatically released upon the exertion of more than a predetermined force to the motor to steer it in the event of an emergency. The releasable restraining device is also automatically engageably upon return of the motor to its first position and can be manually released.
U.S. Pat. No. 3,382,837, which issued to Aumack on May 14, 1968, describes an outboard motor steering control mechanism that relates generally to a device to maintain an outboard motor boat on a previously determined course and more particularly to such a device that adjustably and mechanically determines the positional relationship between the outboard motor steering rod and a boat carrying such motor.
U.S. Pat. No. 1,451,452, which issued to Williams on Apr. 10, 1923, describes a tiller lock. The tiller lock is usable in conjunction with an outboard motor.
U.S. Pat. No. 2,846,896, which issued to Allen on Aug. 12, 1958, describes an outboard motor steering stabilizer. The device is adapted to be utilized in conjunction with an outboard motor and more particularly to a device for holding the tiller in a selected position against movement of the tiller due to vibrations so that a fisherman or other user of the outboard engine need not tend the tiller but may be engaged in fishing or be occupied elsewhere.
U.S. Pat. No. 1,593,823, which issued to Gleason on Jul. 27, 1926, describes a tiller positioning device. The device is usable in conjunction with an outboard motor.
U.S. Pat. No. 4,372,241, which issued to Tritt on Feb. 8, 1983, describes a rudder assembly for sailboats and the like which comprises a rudder support frame pivotally attached to the stern portion of a boat, a substantially horizontal tiller fixedly attached to the upper portion of the rudder support frame, a rudder blade pivotally coupled to the rudder support frame, a rudder blade control mechanism including kickup control arm pivotally coupled to the upper portion of the rudder blade and an interconnecting kickup control member pivotally coupled between the kickup control arm and the substantially horizontal tiller to selectively move the rudder blade between a first or lower position and a second or upper position. The mechanism further includes a lock member fixedly attached to the kickup control arm disposedly to selectively engage the substantial horizontal tiller to lock the rudder blade in the lower or upper position.
The patents described above are hereby explicitly incorporated by reference in the description of the present invention.
In view of the prior art, it would be significantly beneficial if an outboard motor could be provided with a simple and generally inexpensive mechanism that allows the boat operator to lock the outboard in a preselected position, such as a central position.